1. Field of the Invention
The present invention relates to a muffler that inhibits reduction in engine performance and reduces exhaust noise volume.
2. Description of Related Art
A conventional muffler has a front chamber in which a catalyst is provided, an expansion chamber, and a conduit that passes through the expansion chamber. Holes are formed in a side surface of an upstream end portion of the conduit that protrudes in to the front chamber. Exhaust gas from an engine flows into the conduit from the holes of the protruding section, and then flows out to the expansion chamber from the conduit at the downstream side thereof. Then, the exhaust gas flows into the conduit again at the downstream side and is exhausted to the open air from a downstream end of the conduit (see, for example, JP-A-2005-90237 (FIG. 3)).
A motorcycle equipped with such a muffler can reduce unpleasant noise and generate a pleasant exhaust sound. Thus, a rider of the motorcycle can enjoy the exhaust sound generated by the muffler in addition to the engine noise.
However, because attention has been focused on achieving a pleasant exhaust sound, not enough consideration has been given to reducing exhaust noise volume.